The use of solar energy for interior illumination has been understood for centuries. Common window glass, and sky lights are known to virtually all styles of architecture and building design. Solar tracking devices have been used to illuminate interior areas. These devices require mechanical tracking systems for following the sun's apparent motion across the sky. Stationary light shelves extending outwardly away from building side windows have also been used to increase solar illumination.
Refractive systems are also known to increase solar illumination within a building. An example of such a system is disclosed in the present inventor's prior patent (U.S. Pat. No. 4,329,021, issued May 11, 1982). A nontracking reflective structure for vertically illuminating an interior space is also disclosed at the University of Minnesota Civil/Mineral Engineering Building in Minneapolis, Minn. This device has two generally horizontally extending reflective surfaces and provides diffuse solar illumination through the roof.
The present invention provides solar illumination through a side wall, and is capable of illuminating a large area such as a warehouse, or commercial space. The device allows solar illumination to effectively illuminate each floor of a multifloor building, which is difficult or impossible with a vertical system. The present invention is believed to be a true advance in the state of the art as its structure and installation are simple, economical, and versatile. Within the concept of the present invention, the installation of a concentrator for a given latitude is straight forward. A number of structures are present which allow the intensity of illumination to be controlled.